denorm_­present
if the type allows subnormal values
(variable number of exponent bits)203,
denorm_­absent
if the type does not allow subnormal values,
and
denorm_­indeterminate
if it is indeterminate at compile time whether the type allows
subnormal values.

A type is modulo if, for any operation involving +, -, or
* on values of that type whose result would fall outside the range
[min(), max()], the value returned differs from the true value by an
integer multiple of max()- min()+1.